Author Topic: Which groove on the carb needle?  (Read 824 times)

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Offline the architect

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Which groove on the carb needle?
« on: February 26, 2010, 01:07:31 PM »
'75 cb750.

I'm working on a carb rebuild. I've read that the factory puts the clip on the needle on the middle groove.  But, when I got mime apart, a PO had them set on the very last groove (bottom most groove I'd you're holding them with the point down).

So, my question:  what groove would be best for my setup?  I know it can vary, bit I need a good starting point.

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Offline Jim F

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Re: Which groove on the carb needle?
« Reply #1 on: February 26, 2010, 01:11:50 PM »
Are you going to re-jet the bottom end as well as the top end?

If so and the stock set up is in the middle of the needle
and this is just a seat-of-the-pants tuning, then raise your needle (lower the clip)
one groove and start there

This will rich en up the mid range a little but again its just seat of the pants tuning

good luck

Jim
2002 RC51 1000 (SP2)
1983 GS1100EC Suzuki
2002 998 Dukati (Customers Bike)
1992 KTM500 2 stroke
1975 CB750/836 Honda
1978 GS750/840 Suzuki